This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 1 | 9 |
| 2 | 81 |
| 3 | 287 |
| 4 | 981 |
| 5 | 2920 |
| 6 | 9039 |
| 7 | 28681 |
| 8 | 89623 |
| 9 | 278652 |
| 10 | 872602 |
| 11 | 2730176 |
| 12 | 8525256 |
| 13 | 26645271 |
| 14 | 83307020 |
| 15 | 260355204 |
| 16 | 813693708 |
| 17 | 2543369350 |
| 18 | 7949447810 |
| 19 | 24845860649 |
| 20 | 77657127110 |
| 21 | 242721701342 |
| 22 | 758634528231 |
| 23 | 2371142647768 |
| 24 | 7411113488204 |